diff --git a/extensions/voice-call/src/manager.closed-loop.test.ts b/extensions/voice-call/src/manager.closed-loop.test.ts
index 298ccf4964b0..1aaf2cf09cdf 100644
--- a/extensions/voice-call/src/manager.closed-loop.test.ts
+++ b/extensions/voice-call/src/manager.closed-loop.test.ts
@@ -1,4 +1,4 @@
-import { describe, expect, it } from "vitest";
+import { describe, expect, it, vi } from "vitest";
 import { createManagerHarness, FakeProvider, markCallAnswered } from "./manager.test-harness.js";
 
 function requireCall(
@@ -20,6 +20,18 @@ function requireTurnToken(provider: Awaited<ReturnType<typeof createManagerHarne
   return firstStart.turnToken;
 }
 
+function expectTranscriptWaiter(
+  manager: Awaited<ReturnType<typeof createManagerHarness>>["manager"],
+  callId: string,
+) {
+  const waiters = (
+    manager as unknown as {
+      transcriptWaiters: Map<string, unknown>;
+    }
+  ).transcriptWaiters;
+  expect(waiters.has(callId)).toBe(true);
+}
+
 describe("CallManager closed-loop turns", () => {
   it("completes a closed-loop turn without live audio", async () => {
     const { manager, provider } = await createManagerHarness({
@@ -32,7 +44,10 @@ describe("CallManager closed-loop turns", () => {
     markCallAnswered(manager, started.callId, "evt-closed-loop-answered");
 
     const turnPromise = manager.continueCall(started.callId, "How can I help?");
-    await new Promise((resolve) => setTimeout(resolve, 0));
+    await vi.waitFor(() => {
+      expect(provider.startListeningCalls).toHaveLength(1);
+      expectTranscriptWaiter(manager, started.callId);
+    });
 
     manager.processEvent({
       id: "evt-closed-loop-speech",
@@ -107,7 +122,10 @@ describe("CallManager closed-loop turns", () => {
     markCallAnswered(manager, started.callId, "evt-turn-token-answered");
 
     const turnPromise = manager.continueCall(started.callId, "Prompt");
-    await new Promise((resolve) => setTimeout(resolve, 0));
+    await vi.waitFor(() => {
+      expect(provider.startListeningCalls).toHaveLength(1);
+      expectTranscriptWaiter(manager, started.callId);
+    });
 
     const expectedTurnToken = requireTurnToken(provider);
 
@@ -122,11 +140,7 @@ describe("CallManager closed-loop turns", () => {
       turnToken: "wrong-token",
     });
 
-    const pendingState = await Promise.race([
-      turnPromise.then(() => "resolved"),
-      new Promise<"pending">((resolve) => setTimeout(() => resolve("pending"), 0)),
-    ]);
-    expect(pendingState).toBe("pending");
+    expectTranscriptWaiter(manager, started.callId);
 
     manager.processEvent({
       id: "evt-turn-token-good",
@@ -158,7 +172,10 @@ describe("CallManager closed-loop turns", () => {
     markCallAnswered(manager, started.callId, "evt-multi-answered");
 
     const firstTurn = manager.continueCall(started.callId, "First question");
-    await new Promise((resolve) => setTimeout(resolve, 0));
+    await vi.waitFor(() => {
+      expect(provider.startListeningCalls).toHaveLength(1);
+      expectTranscriptWaiter(manager, started.callId);
+    });
     manager.processEvent({
       id: "evt-multi-speech-1",
       type: "call.speech",
@@ -171,7 +188,10 @@ describe("CallManager closed-loop turns", () => {
     await firstTurn;
 
     const secondTurn = manager.continueCall(started.callId, "Second question");
-    await new Promise((resolve) => setTimeout(resolve, 0));
+    await vi.waitFor(() => {
+      expect(provider.startListeningCalls).toHaveLength(2);
+      expectTranscriptWaiter(manager, started.callId);
+    });
     manager.processEvent({
       id: "evt-multi-speech-2",
       type: "call.speech",
@@ -212,7 +232,10 @@ describe("CallManager closed-loop turns", () => {
 
     for (let i = 1; i <= 5; i++) {
       const turnPromise = manager.continueCall(started.callId, `Prompt ${i}`);
-      await new Promise((resolve) => setTimeout(resolve, 0));
+      await vi.waitFor(() => {
+        expect(provider.startListeningCalls).toHaveLength(i);
+        expectTranscriptWaiter(manager, started.callId);
+      });
       manager.processEvent({
         id: `evt-loop-speech-${i}`,
         type: "call.speech",
diff --git a/extensions/voice-call/src/manager.notify.test.ts b/extensions/voice-call/src/manager.notify.test.ts
index a325f119dd64..c67e6cc3fdfe 100644
--- a/extensions/voice-call/src/manager.notify.test.ts
+++ b/extensions/voice-call/src/manager.notify.test.ts
@@ -91,7 +91,7 @@ function requireSingleStartListeningCall(provider: FakeProvider) {
 type HarnessManager = Awaited<ReturnType<typeof createManagerHarness>>["manager"];
 
 async function waitForPlaybackDispatch() {
-  await new Promise((resolve) => setTimeout(resolve, 0));
+  await new Promise<void>((resolve) => setImmediate(resolve));
 }
 
 async function initiateCallWithMessage(